Pakistani drivers stand on top of a tanker, used to transport fuel to NATO forces in Afghanistan, parked near oil terminals in Pakistan's port city of Karachi in May 2012.

US Secretary of State Hillary Clinton's statement that "we are sorry" about a deadly border crash led to Pakistan reopening military supply routes and resolved one contentious issue between the two nations.

The US relationship with Pakistan has been battered by a series of disputes as the Obama administration plans its exit from the 11-year war in neighboring Afghanistan. Pakistani officials chose to accept Clinton's comments as the apology they had demanded, leading to the supply-lines deal that was the first evidence of headway in months on issues that have held up more than $1 billion in US funding for Pakistan.

While military supplies may begin moving to coalition forces in Afghanistan as early as today, tensions persist. The US wants Pakistan to crack down on Haqqani Network extremists, who launch attacks on coalition forces in Afghanistan from Pakistani havens, and the Pakistan government wants the US to end CIA drone strikes aimed a terrorists within its territory.

Resolving the supply-routes dispute "was one of the easiest tasks," Shuja Nawaz, director of South Asia Center at the Atlantic Council, a policy-research group in Washington, said in an interview. There are so many remaining issues "that I don't expect there to be sweetness and light in this relationship for quite a while," he said.

Progress may unravel with the next "massive drone strike or a US raid into Pakistan to get a high-value target or a successful strike by Haqqanis inside Afghanistan," Nawaz said.

Reopening transit

Pakistan said yesterday it would reopen supply routes to transport non-lethal material and supplies to coalition forces, as well as weapons for the Afghan military. The transit route had been shut since November, after a US military strike mistakenly killed 24 Pakistani troops and the country's officials demanded an apology.

While Clinton didn't use the word "apologize," Qamar Zaman Kaira, Pakistan's information minister said in Islamabad that the routes are being reopened after the US was forced "to apologize to the Pakistani people and its nation. If we go into the nitty-gritty of her words, then people will take it one way or another," he said.

A Pentagon investigation found in December that US forces raiding an Afghan village near the border took heavy machine-gun fire from inside Pakistan and thought it came from insurgents because the US ground commander had been told there were no Pakistani troops in the area. Return fire from US helicopters killed the 24 Pakistani troops.

"˜Deepest regrets'

Clinton said in a statement that she offered "deepest regrets" over the accidental killings during a conversation yesterday with Pakistan's Foreign Minister Hina Rabbani Khar.

"Foreign Minister Khar and I acknowledged the mistakes that resulted in the loss of Pakistani military lives," Clinton said yesterday. "We are sorry for the losses suffered by the Pakistani military. We are committed to working closely with Pakistan and Afghanistan to prevent this from ever happening again."

Pakistani officials also demanded that the US vacate the Shamsi air base, which had been used by the CIA to carry out drone strikes in Pakistan's tribal areas.

Clinton didn't discuss in her statement the use of drones, which the Obama administration has called an invaluable tool in combating terrorists, and Kaira said only that Pakistan will seek to persuade the US to end drone attacks as counter- productive. Pakistan has said the attacks sometimes kill civilians and fuel public anger toward the US and the Pakistani government.

Pakistan's help

The US seeks Pakistan's cooperation in halting cross- border attacks, allowing the transport of coalition supplies, and at least tacitly accepting drone strikes on terrorist targets in Pakistan such as the one in June that killed al- Qaeda's second-in-command.

Pakistan's Defense Committee of the Cabinet agreed to reopen the transit routes to help the US and NATO reduce their cost of drawing down forces from Afghanistan as well as to aid in the reconciliation process in Afghanistan, according to a statement from Pakistan's embassy in Washington.

The closing of the supply routes forced the US and the North Atlantic Treaty Organization to send material and equipment from the north, through Central Asia, at an added cost that Defense Secretary Leon Panetta has estimated at about $100 million a month.

China incident

Clinton's statement yesterday was similar to the wording the US offered China in the wake of a 2001 incident when a US spy plane collided with a Chinese jet fighter, Nawaz said.

In that case, two Chinese jets intercepted a US Navy EP-3 spy plane just off the coast of Hainan, an island in the South China Sea. One of the Chinese jets crashed and its pilot died. The US aircraft, which landed on Hainan, and its crew of 24 were detained by the Chinese for 11 days until the US ambassador said the US was "very sorry" for the the loss of the pilot and unauthorized landing of the American aircraft.

Asked yesterday if the US agreed to pay more than previously for use of the Pakistan supply routes, State Department spokeswoman Victoria Nuland said, "We are paying the exact same amount as we were paying before."

Transit costs

The US will pay about $250 per container as a basic operational cost, Nadeem Hotiana, a spokesman for Pakistan's embassy in Washington said in an e-mail. That is the same as the U.S paid before the routes were shut and Pakistan wouldn't charge any additional transit fees, he said.

Senate Armed Services Committee Chairman Senator Carl Levin, a Michigan Democrat, said in an interview in June that Pakistan had been demanding the US pay as much as $5,000 per container of NATO supplies shipped over its routes, up from about $250 each before the routes were reopened.

In addition, the reopening of supply routes may free up as much as $1.2 billion in coalition support funds for Pakistan from fiscal year 2011 that the US has withheld.

"Pakistan does not want to isolate itself," Mutaher Ahmed, a professor of international relations at the University of Karachi, said in a telephone interview yesterday. "Damage control came late, but now this will help Pakistan repair ties with other countries, especially the United States."

Political risks

For the Pakistan government of newly installed Prime Minister Raja Pervez Ashraf, which faces parliamentary elections by early next year, agreeing to allow the NATO trucks to once more roll across the frontier carries political risks. A June 27 survey of attitudes by the Pew Research Center found that 74 percent of Pakistanis considered the US to be an enemy, up from 69 percent in 2011.

Panetta, who said last month that the US was losing patience with Pakistan, yesterday welcomed its decision to reopen the routes.

"As I have made clear, we remain committed to improving our partnership with Pakistan and to working closely together as our two nations confront common security challenges in the region," Panetta said.

US-led coalition troops in Afghanistan are aiming to weaken the Taliban insurgent movement before handing over security responsibilities to Afghan forces ahead of a withdrawal from the country in 2014. In the past three months, the Taliban have attacked government office buildings, including the parliament, the US, German and British embassies and the offices of two provincial governors.

US and Afghan officials have blamed a number of the strikes on the Haqqani network, a militant group based in Pakistan and affiliated with the Taliban.

Graphic showing border crossing points between Pakistan and Afghanistan, reopened to NATO supplies after a bitter stand-off between the US and Pakistan over the loss of life in a botched air raid last November